Coating machine



APatented May 1s, 19453 g Utri-Iran *Par-'ENT f OFFICE e L I e l Ycoarrzisiicnmn i i y p Bannay, Los Angeles, oeuf. Application January 6,1939, Serial No. 249,574 l (Cl. el-so) 4 Claims.n

This invention 'pertains to improved meansfor tons and various othercontainers itis desirable to render thehboxes and containers water relsistant;- Various lacquers, resinous coating compositions orcompositions containing waxes. latex', rubber 'condensation products,etc., have been applied. :In mostins'tances these resinous, rubbery orwaxy compositions contain a volatile. solvent at the time they arevapplied to the paper or other stock from which `the box or container isto be made. Numerous problems are encountered in the applying process,among which is theproblem of forming a lm of uniform thickness.Anotherproblem is thecontrol of solvent vapors.

seallngor lcoating'compositions may be applied to individual cards or,pieces of `fibrous material. These and other objects, uses, advantagesand l adaptations ofthe invention will become apl e like. In t lthe-manufacture of boxes, hoods for bottles, car- 4 parent to thoseskilled in vthe vart from' the following detailed description f certainillustrative forms. f A u In order toltfacilitate understanding,reference will-be had to the appended drawings, in which:

j Fig. 1 diagrammatically illustrates an arrangement of elements wherebya continuous strip oi fibrous material may be coated on bothsides.

` Fig. 2 is an enlarged view of one form of appli'- i apparatus for usein applying a sealing coating kThe present vinvention `is directedtowards means whereby av continuous, uniform, homogeneous'fllm ofcoatingmaterial may be applied without permitting large quantities ofsolvents to be lost. The apparatus is'particularly adapted to theapplication of a lm or coating to coni tinuous strips of paper or thelike. j

`Generally stated, the invention comprises supplying a coating liquid inthe form of a'continuous stream through a narrow aperture onto thelsurface to be coated and maintaining yielding at right angles to theaperture." In this manner a uniform` film` of the coating composition is`applied to the surface of the strip, a portion of Vthat surface(opposite saidl aperture). being in direct contact with a body ofcoating liquid.

An object of this invention, therefore, is to provide an improvedapparatus for coating pa per, wood and other` fibrous materialsl with asealingor coating composition. i i

Another object is to provide anV apparatus' whereby continuous s'tripsof fibrous material may be coated on oneor both sides with a waterresistant or other sealing or coating composition in `a continuousmanner.

A further objectA is to provide means whereby to individual blanks ofmaterial to be coated.

Fig. 4 is an enlarged vertical section through a portion of thedevice/shown in Fig.r3.

The arrangement shown in Fig. l is particular- 1y adapted for use incoating a continuous strip of materialonboth sides with a suitablesealing" or coating composition. A tank for this sealing `solution isindicated at I0. As stated hereinbefore, the sealing solution maycomprise a. solution of gums,` resins, lacquer-s, waxes and rubber orrubber-like products in a suitable solvent. Or-

dinarlly, relativelyv volatile solvents are ein- `ployed.` An acryloidtype ofl resin or synthetic vplastic in a volatile solvent such as butylacetate, is an example of one -form of coating solution. I'he coatingsolution from tank I0 mayrthen be circulated by a pump lithrough linesI2 into a' back to the tank I0. In this manner a continuousohead ofcoating solutionis maintained in the a g `surge tank I3. A line or linesI8 connect'the ylower portion of the surge tank Ilwith the applicatorsHand I5. n. Y

Fig. 2 is an enlarged` vertical section through one 'of the applicators,say applicator I'4. As there ,shown the applicator is in the form of ahorizontally extending tube, one end of which is' in communication withthe supply line i8 and uthe other end of which is preferably' closed.Longitudinally extending along the tube I4` Ais a slot or aperture 2li.Opposing said slot or aper- Vil of the applicator. A stationarysupporting member 22 is diagrammatically illustrated, the presser plate2| being attached to the bolt 23 extending through the stationarysupport. Spring means 24 yieldably press the presser plate against' theaperture.

A supply reel 26 of continuous strip material over a suitable roller,such as the roller 21. and

'then past the applicator I4, the strip material -even though ysuchcontinuous strip reverses its direction. For example; between the`rollers3l and 32 it travels from right to left whereas between the rolls33 and 34 it travels from left to right. Thereafter the continuous stripmaterial may pass over the rollers 35 and 36 and be discharged from thedrier. This strip material now passes past the applicator I5 whichapplies an- ,other film of sealingand coating material to the oppositeside of such continuous strip 28 wherey to be coated may discharge thestrip of material adapted to coat individual sheets or blanks of fibrousmaterial. at-60 and such blank passes through feed rolls 6 I; the blankmay be fixed tov progress from left to right (Fig. 3) in anypsuitablemanner, as forij example by means of a conveyor belt or belts. feedrolls, or thev like. As the leading edge of the blank 60 contacts apivoted key 62 in the form lmember 68 acts as a valve and is providedwith a discharge slot 10 and an inlet opening 1I. The inlet opening 1|is always in communication with the main supply linev 12 which, for-purposes understood later, may be a flexible tube or hose connectingthe applicator 63 with a supply tank 13. When the solenoid 66 isactuated and the lever 61 is pulled down, the discharge opening 10 ofthe rotary valve member 68 places the,

- interior of the applicator in communication with upon the strip passesover a roll 31 and returns u to the drier wherein it is trained overrollers such as the rollers 38, 39, and 4|. Eventually the continuousstrip is discharged from the drier 30 and collected upon a take-up reel42 which is positively driven. During the entire operation thecontinuous strip material 28 is maintained under tension and isprogressed past the applicators and through the drier by reason of thepull exerted upon the take-up reel 42. If desired, certain of therollers, such as the rollers 31 and 39, may be frictionally driven so asto facilitate the forward travel of the continuous strip through themachine.

' By again referring to Fig. 2 it will benoted that the trailing ,edgeof the aperture 20 is relatively narrow, the exterior of the tubularcasing of the applicator being milled out slightly as indicated at 50.In other words, the trailing edge adjacent the longitudinal aperture 20preferably has an action similar to that of a knife for smoothing outthe applied composition or solution. The

' 1 and z-wm be evident many one skilled in the art from the descriptiongiven. It is to bek noted that the coating solution is suppliedto theapplicators under a' constant gravity head so that no pulsations orchangesin pressure exist. Furthermore, the disadvantages incidental tospraying or paintingbyhand are not encountered,v

the entire system being totally enclosed. The

- surface of the paper 28 is in communication with the interior of theapplicator I4 and a relatively thin but solid body of. fluid is incontact with such surface through the slot 20. Ordinarily the slot 20may measure from about 0.05 to 0.1 inch in, width, it being understoodthat the Width yof this slot will depend upon the viscosity and othercharacteristics of the sealing solution and the head or pressure atwhich it is supplied to the interior ofthe applicator.-

. and cut back as shown at 85.

, Figs. 3 and 4 particularly relate to a device 75 the aperture`69.

The position of the original contact 62 is correlated with the lag ofthe relay 6,5 so that by the time the leading edge of the blank 60assumes a position immediately below the slot 69 of the applicator 63,the rotatable valve 68 has been moved into its operative 4position andthe sealing` fluid is being discharged through the slot 69. As soon asthe trailing edge of the blank 60 releases the contact 62, the solenoid66 is deenergized. and the valve returns to its original closed position(indicated in Fig. 4) by reason of the spring 14.

In order to accommodate blanks 60 of varying thickness, the entireapplicator 63 may be pivotally suspended as up`0n the lever arm 80 froma stationary support 8|. One end of the lever arm` may be held down bymeans of a set screw 82. B y adjusting the set screw 82, the entireapplicator 63 may be caused to rise or fall and thereby positioned at`any desired height with respect to the table, conveyor belt or otherplane through which the blanks 60 move.'4 4Since the storage tank 13 mayalso be stationary. the flexible tube 12 accommodates for differences inoperative height assumed by the applicator 63.

As in the case of the applicator described in connection with Figs. 1and 2, the trailing edge adjacent the discharge slot 69 is relativelythin s groove adjacentthe rear edge ofthe opening or port acts as adoctor knifevand prevents accumulation of coating composition infrictiona1 contact with the freshly coated sheets.

The coating compositions may therefore be applied to one or -both sidesof acontinuous strip or to pieces of sheet material. The coatingcompositions may be water proof, water-resisting, waxy, oi' a natureadapted to strengthen the fibrous sheet material, or of a naturepermitting the sheet material to become adhesive upon the furtherapplication of solvents, heat or heat and pressrure.` Some coatingcompositions need not contain a. volatile solvent at the time of theirapplication to the sheet material. When compositions of the typedescribed by Abrams in Patent #2,054,115 are applied, for example. itmay be desirable .to use `a steam jacket or other heating One such blankis indicated 1 asians means around the applicators for the purpose ofliquefying the composition and facilitatingcoating. Coatings of thislast mentioned type are particularly of advantage where the coatedmaterial is to be used in making bottle hoods and containers sinceblanks cut from such coated sheet material can later be preheated andthen pressed to the desiredvshape, the composition acting as athermoplasticV or vulcanizing substance bonding the folded or pressedportions together without n they use of' added adhesives. Resinouscomposll tions in hot or melted condition can also be applied by themethod or apparatus of my invention.

A Iclaim:

1. In an apparatus for coating sheet material with protective coatings,an applicator comprising a tubular member provided with a longitudinallyextending slot having substantially parallel walls, said slot forminganapplicating port defined by edge portions, a gradualLv curving surfaceon said tubular member leading to lthe front edge portion of said slot,said tubular member material across the slot` and virtually tangentsheet material and coating applied thereto,

whereby said last-named edge of the slot is thin and adapted to act as asmoothing knife edge;

3. In anapparatus for coating sheet material4 with protective`coatings:l an applicatorcomprisving a tubular member provided with alongitudinally extending slot in communication with the interior of saidmember, the slot having plane, substantially parallel walls, the slotforming an `applicating' port defined by edge portions integral withsaid tubular member a gradually curving surface on said tubular memberleading to the front edge portion of the slot; a reentrant surfaceadjacent the rear edge of the slot and parallel to the'slot. saidreentrant surface defining a narrow rear edge portionto the slot, suchnarrow rearedge portion being adapted to act as a I smoothing knifeedge: means fordrawing sheet to the applicator at said slot; and meansfor supi plying liquid coating to-the tubular member and being providedwith a re-entrant curved surface f adjacent the rear'edge portion oisaid slot, said re-entrant curved surface being parallel to said slotbut spaced therefrom whereby said rear edge Iportion is rendered narrowand is adapted to act as a smoothing knife edge. a rotary valve in saidtubular member, said `valve being adapted t'o open and kclose saidapplicating port, means for moving sheet'material along a line of travelpast ,said port, and means operated by sheets or material advancingtoward said port for said rotary valve to open said port. 2'. Anapparatus for'applying coating in liquid form to the. surface ofsheetmaterial comprising: an applicator having a transversely rounded surfaceprovided with a slot extending lengthwise 1 thereof, means for supplyingliquid coating material to the slot, means for drawing sheet materialsubstantially` transversely to theaxis of the actuating slot by gravity.l.

4. In an apparatus for coatingsheet material with protective coatings:an applicator compris'- ing a tubular member provided with alongitudinally extending slot having substantially parallel p walls,said slot forming an appiicating port del fined by edge portions, agradually curving surface-on said tubular member leading to the frontedge portion of said slot, said tubular member being provided with areentrant curved surface adjacent the rear edge portion of said slot.said reentrant curved surface being` parallel to said slot .but spacedtherefrom whereby said rear edge slot and in contact with the edgesthereof and substantially tangentialiy to the rounded surface of theapplicator, said rounded surface having a longitudinally extendingrecess formed therein i and parallel to such slot and closely adjacentthat edge of the slot which is last in contact with the portion isrendered narrow and is adapted to act as a smoothing knife edge;a'rotary valve in said tubular member, said valve being adapted to openand close said applicating port: a lever arm pivL' otally supportingsaid applicator;- means for ad-f justably positioning the lever arm andapplicatorV with respect tola line of travel oi'sheet material; means|for moving'sheet material along the line`oftravelnastsaidport:andmeausoperatcdliy sheets of material advancingtoward said port for actuating said rotary valve to open said port.

DON RAY.

